利用键盘作为输入，在单片机内部实现运算，并且在LCD显示器上显示的简易计算器。包含三个模块：键盘模块、单片机模块、液晶模块。-Using the keyboard as the input, the operation in the MCU internal, simple calculator and displayed on the LCD display. Contai. Contains three modules: keyboard module, microcontroller mo